Armed police raided a string of addresses in the two areas and blew the doors off some properties to gain entry.

The men appeared on Friday accused of planning to build a bomb and carry out a terrorist attack in the UK.

The two appeared in custody at Westminster Magistrates Court via video link from Leeds Magistrates Court.

Both men, of Iraqi origin, spoke only confirm their name, age and address, and are both charged with a single count of engaging in the preparation of an act of terrorism.

Thomas Halpin, prosecuting, said: "Both are jointly charged with a single offence of preparation to commit acts of terrorism under section five for the terrorism act 2006."

Andy Star, who has appeared at court having been arrested in ChesterfieldCredit:
Ben Lack Photography Ltd

He added: "This is a case in which the Crown say both defendants were researching, developing and manufacturing chemicals to make explosive substances so they could be used in an improvised explosive device with a view to committing acts in the UK."

On the December 19, Star, who runs the Mermaid Fish and Chip shop in Chesterfield, and Salah were arrested at their respective home addresses.

Deputy Senior District judge Tanweer Ikram said: "I am sending each of you to the Central Criminal Court, and your next hearing date there will be on January 19."

Star, of Chesterfield, and Salah, of Sheffield, were remanded in custody to appear at the Old Bailey on January 19.

The police raids were carried out by Counter Terrorism Policing North East and supported by police officers in Derbyshire and South Yorkshire.

A total of 36 people have been killed by four terrorist attacks in the UK in 2017, but counter terrorism police and MI5 say they have also foiled a string of potential attacks.

Salman Abedi killed 22 in May when he blew himself up at Manchester Arena in crowds leaving an Ariana Grande pop concert. Three attackers killed eight in a van and knife rampage on London Bridge in June.

Andrew Parker, director general of the Security Service, in October said the country was now facing a tempo of terrorism threat he had not seen before in his 34-year-career.

MI5 disclosed earlier this year that counter terrorism officers were running more than 500 operations, involving about 3,000 subjects of interest.

Yesterday (FRI) Dominic Raab, the Justice Minister, proposed extending the number of terrorism offences where unduly lenient sentences could be challenged.

He suggested extending the scheme to cover offences such as tipping off suspects under investigation; those who breach monitoring conditions; and individuals engaging in hoaxes involving toxic substances.

He said the Government was also investing £50 million extra in counter-terrorism policing next year and the number of armed police will increase by more than 1,000 over the next two years.